Datasheet

15
AT30TSE752A/754A/758A [DATASHEET]
Atmel-8854G-DTS-AT30TSE752A-754A-758A-Datasheet_102014
6. Registers
The AT30TSE752A/754A/758A contains eight registers (a Pointer Register and seven data registers) that are used to
control the operational mode and performance of the temperature sensor, store the user-defined high and low
temperature limits, and store the digitized temperature measurements. All accesses to the device are performed using
these eight registers. In order to read from and write to one of the device's seven data registers, the user must first select
a desired data register by utilizing the Pointer Register.
The device incorporates both volatile and nonvolatile versions of the Configuration Register, the T
LOW
Limit Register, and
the T
HIGH
Limit Register. Upon device power-up or reset, the AT30TSE752A/754A/758A will copy the contents of the
Nonvolatile Data Registers into the Volatile Data Registers. Both the volatile and Nonvolatile Data Registers can be
modified separately provided that the registers are not locked or locked down; however, all temperature sensor related
operations, such as responses to high and low temperature conditions, are based on the settings stored in the volatile
versions of the registers only. Therefore, if the Nonvolatile Data Registers are updated with new values, then the
contents of the Nonvolatile Data Registers should be copied to the Volatile Data Registers (see Section 9.1, “Copy
Nonvolatile Registers to Volatile Registers” on page 34)
Table 6-1. Registers
The Configuration Register, despite being 16-bits wide, is compatible to industry standard LM75-type temperature
sensors that use an 8-bit wide register in that only the first 8-bits of the Configuration Register need to be written to or
read from.
6.1 Pointer Register
The 8-bit Write-only Pointer Register is used to address and select which one of the device's seven data registers
(Temperature Register, Configuration Register, T
LOW
Limit Register, T
HIGH
Limit Register, Nonvolatile Configuration
Register, Nonvolatile T
LOW
Limit Register, or Nonvolatile T
HIGH
Limit Register) will be read from or written to.
For Read operations from the AT30TSE752A/754A/758A, once the Pointer Register is set to point to a particular data
register, it remains pointed to that same data register until the Pointer Register value is changed.
Example: If the user sets the Pointer Register to point to the Temperature Register, then all subsequent reads from
the device will output data from the Temperature Register until the Pointer Register value is changed.
Register Address
Read/
Write
Size Power-on Default
Factory
Default
Pointer Register n/a W 8-bit 00h n/a
Temperature Register 00h R 16-bit 0000h n/a
Configuration Register 01h R/W 16-bit Copy of Nonvolatile Configuration Register n/a
T
LOW
Limit Register 02h R/W 16-bit Copy of Nonvolatile T
LOW
Limit Register n/a
T
HIGH
Limit Register 03h R/W 16-bit Copy of Nonvolatile T
HIGH
Limit Register n/a
Nonvolatile Configuration Register 11h R/W 16-bit Last Programmed State 0000h
Nonvolatile T
LOW
Limit Register 12h R/W 16-bit Last Programmed State 4B00h (75C)
Nonvolatile T
HIGH
Limit Register 13h R/W 16-bit Last Programmed State 5000h (80C)